Life Below

Niue has had a thorough buffeting from Cyclone Heta in January 2004, in fact perhaps the worst case recorded in living memory. Where people thought to be safe from the sea, some 25m above sea level, this was proved wrong, even though a disaster of this magnitude may never happen again. Under water, the sea received an equal hiding resulting in totally barren areas, completely stripped of life. But on the very sheltered Western side of the island, cyclones are normal fare, occurring sufficiently frequently to maintain a barren seascape. Yet these barrens are covered in fine algae, growing at maximal rates for the dearth of nutrients dissolved in these ultra-clear waters. The barrens maintain armies of grazers, from tiny snails to nocturnal sea urchins and day-time grazing fish. One could say that they maintain more life than the coral-clad slopes of the other side of the island.

The other side, although not visited by the worst of cyclones, receives continuous buffeting from large ocean swell, propelled by never-ending South-East trade winds experienced as a refreshening cool sea breeze all day and night. We ventured a dive there to bring back unique photos of what the best of Niue under water hopes to offer. Diving here is quite dangerous, being swept to and fro at three times walking speed, swinging ten metres over sharp corals, ready to be ripped to shreds. Fortunately this seascape can also be found in safer waters, near the Matavai Resort (matavai= kingfish Seriola sp).

The photos presented here were all taken in September 2004, about 9 months after Cyclone Heta struck. They hope to give you an impression of what Niue looks like, both above and under water, and how it is recovering. To inform yourself about Niue’s history, geography, geology and much more, visit the extensive section about Niue.

This red turfing seaweed is highly successful but is somehow not eaten

Near Alofi this white mushroom seaweed can be found. It is not eaten by the many grazers.

Inside a dark canyon under a foam umbrella, coral can grow only slowly as also the red coralline algae. Surgeonfish hang around to keep this environment clean.

A diver finds slow growing coral under a roof window inside a cave. Such leaves of coral may die back, then grow over the old structures again, for hundreds of years.

Slow growing reddish corals in a roof-lit cave. No signs of cyclone damage on these rather old corals. Red leaf coral, Montipora sp.

Where it becomes pitch dark, the night shift sleeps like these red squirrel fish. This photo was taken with preset distance and other settings, pointing the camera into a dark hole. Sargocentron spiniferum

Caves and canyons are found everywhere, fun to explore. The ones near Alofi support growth of green algae.

Detailed corals

Brown coral polyps half extended by day to catch the most sunlight. Corals have brown algae in their tissues.

At night the coral polyps compete for space while trying to catch small plankton particles (Favia sp)

Closeup of brain coral, Leptoria sp.

During the day the polyps hide deep between the hard protecting ribs

By day this encrusting Porites coral has its polyps withdrawn but bright sunlight penetrates. Both Porites and Acropora are found in rockpools as they survive being out of the water for a while.

Detail of Acropora coral shows complicated structure and small polyps. This coral follows a complicated growth pattern by which it eventually forms a mushrooming plate above other corals

Detail of acropora plate coral showing how it creates maximal surface area and space in-between for its polyps.

A type of honeycomb coral extends its tissues by day but retracts its tentacles.
Favia sp.

Banded flag-tail almost invisible just under the surface near shallow rocks. In the foreground an Achilles tang.

Banded flag-tail are almost invisible, but so are the pipers and grey mullets.

Black and white basslet looks like snow when schooling.

These small basslets are found even in very small rock pools. In the back lives a moray eel.

The most prominent fish of Niue is perhaps this tiny rock skipping blenny, living half out of the water. It can move very fast bent in this u-shape which forms two legs: head and tail. Istiblennius edentulus

This rock skipper blenny was photographed above water, where it prefers to be. They are so cute. Istiblennius edentulus

This rock skipper blenny was photographed above water, where it prefers to be. They are so cute. Istiblennius edentulus

Two blennies side by side, related to the rock skipper (male and female?). Little fish like these may well be endemic, which means they are found nowhere else but around Niue

Two blennies of different kind sharing a burrow to watch the photographer. They are so cute.

This purple cardinal fish is out at night to feed on plankton but here it shies away from the diver’s torch

Black spotted pufferfish occurs in many colours from pale to brown and yellow

Little pufferfish are easily approached by night

Tiny black spotted pufferfish in the hand. Arothron nigropunctatus

Pufferfish wedge themselves into a cosy spot and inflate for a good night’s sleep

This common lion fish is dark brown. Lion fish, also called firefish, can deliver painful stings with their back spines

Closeup of brown common lion fish.Pterois volitans

A young brown common lion fish

A rare peacock flounder in Avatele harbour. There is little sandy habitat, but this flounder changes its colours as it moves over various rock forms, and is fascinating to watch. Here it has its swimsuit on, pale with blue flowers. Bothus mancus (Brousonet, 1782)

Most fish are plant eaters, scraping algae off the coral rocks. Here one sees various species of surgeonfish and sergeant-majors.

The larger rock pools are tranquil and hold a lot of fish

The larger rock pools are tranquil and hold a lot of fish

Sea snakes are very common. This one has folded itself into a shallow hole and is sleeping but even so it must surface now and then for a breath of air

Closeup of a sea snake shows sharp eyesight and very small mouth which can still open wide. It has very small fangs backed by a lot of powerful poison.

Closeup of sea snake

A small octopus withdraws into its den. Notice the many grazing snails.

This spotted rock cod is a small grouper.Epinephelus hexagonatus (Bloch & Scheider)

The most amazing of all survivors is this little black urchin, living in the worst of the wave wash, inside its burrows and trenches. With some difficulty also a limpet (centre-right) and a spined snail (top-left) can be found.

This fluffy sea cucumber comes out at night to lick the rocks clean (Stichopus horrens)

On of the most amazing creatures is this large armoured sea cucumber, growing to almost one metre long.

This tube snail lives in a hollow tube cemented to the rock. It catches plankton but also casts a sticky net to be more effective. It then pulls the net in and gobbles its own web inclusive of plankton particles that stick to it

Detail of the tube of a tube snail (Dendropoma maxima)

The giant clam filters seawater for fine plankton. It is sought after because it contains much tasty flesh which can be removed easily without removing the heavy shell, locked into the coral matrix. Tridacna maxima

The tridacna giant clam has a mantle with single-celled plants that grow in sunlight. They provide the clam’s main food. Tridacna maxima.

other invertebrates

This dense feather star comes out by night where it seeks a position in the current.

Detail of a feather star does not quite show its very fine tube feet

This species of feather star does not move much and is out by day

This feather star hides by day. By night it coils up in the glaring dive light

A feather star walking on all legs, pushing from behind and pulling from the front, it walks towards bottom left. They can cover 2-5 metres a minute!

A baby featherstar grows its arms one by one as it matures.

A deep red serpent star on a purple coral is regrowing some of its arms. Leiaster speciosus

This unassuming sea slug is the famous Spanish dancer with its wide wings furled alongside its body. When it swims, it spreads its red wings with white circles, a breathtaking view to behold. Unfortunately, this was the last photo on film. Hexabranchus sanguineus

crustaceans

The weak-shelled shore crab has a beautiful disruptive pattern. It moves very fast with its long legs, both in and out of the water.Grapsus grapsus tenuicrustatus.

The juvenile weak-shelled shore crab is almost invisible.Grapsus grapsus tenuicrustatus

A small crab species, living in pairs along the high tide mark.Plagusia depressa tuberculata. All crabs, shrimps and crayfish carry their eggs until they hatch, which helps survival.

One of many swim crabs by night.Portunus granulatus?

A side-spined paddle crab at night.Charibdis sp?

This flat crab colours well with its protective host, a hollow spined needle urchin. Percnon planissimum

The banded cleaner shrimp lives in pairs for life. During the day they advertise themselves clearly underneath overhangs for their fishy clientele. Stenopus hispidus

Detail of a banded cleaner shrimp. These shrimps are very similar to those found in NZ. It does not risk its life in search of food, because its food is brought towards it as sea lice on the skins of fish.

Banded cleaner shrimp in full glory. Stenopus hispidus

This red cleaning shrimp usually lives near eels and cleans them while sharing in their food